PCI expansion adapter with PC card slot and electronic apparatus provided with the same

ABSTRACT

There is provided a technology for realizing an PCI expansion adapter for a PC card which is connectable to a desktop type personal computer PCI expansion connector using a low profile PCI. The PCI expansion adapter includes an expansion unit which is provided with an electrical connector to a PCI bus, a low profile PCI expansion board provided with a PC card control element and an electrical connector to the PC card, wherein the low profile PCI expansion board and the expansion unit are connected by the electrical connectors mounted on the respective boards.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an electronic apparatus providedwith a low profile PCI slot and a PCI expansion adapter connected to theelectronic apparatus.

[0002] Conventionally, in order to use a PC card for a notebook personalcomputer in a desktop type personal computer, there is used a PCIexpansion card provided with a connector for connecting a PC card and acontrol LSI for controlling the connection with PCI (PeripheralComponent Interconnect) bus.

[0003] On the other hand, in accordance with the recent miniaturizationof a personal computer or the like, a low profile PCI expansion board,which is smaller than a conventional PCI expansion card, is standardizedfor an electronic apparatus such as a desktop type personal computer anda printer by the PCI Special Interest Group. The details thereof aredescribed in the PCI Local Bus Specification Ver. 2.2 and the ECNreferring to the Low Profile PCI Card.

[0004] As shown in FIG. 14, the low profile PCI expansion board is acard edge type board having a connection terminal 63 in a part of itsone edge. The name “low profile” derives from its low profile in theheight direction (the ac direction in FIG. 14) from the motherboard. Thelow profile PCI expansion board is mounted on the motherboard byinserting the connection terminal 63 into a PCI expansion connector 52on the motherboard.

[0005] The PC card is inserted or removed through an expansion slotprovided on the cabinet of an electronic apparatus such as a desktoptype personal computer, while the mounting direction of the expansionslot may be limited to the ab direction shown in FIG. 14 due to thepositional relationship between the cabinet of the electronic apparatusand a motherboard therein.

BRIEF SUMMARY OF THE INVENTION

[0006] A parts mountable area on the low profile PCI expansion board 61has a length of 56.15 mm in the ac direction except the connectionterminal section 63. Further, the minimum horizontal width of acommercially available PC card slot 62 is approximately 62 mm (forexample, the model JC21EJ-FSN20 manufactured by Japan AviationElectronics Industry, Limited). Thus, it has been impossible to mountthe PC card slot 62 so that the card insertion/removal directioncorresponds to the ab direction as the case of a conventional PCIexpansion card. In addition, because of restriction under the standard,it has been also impossible to employ the structure in which the PC cardinsertion/removal direction is perpendicular to the parts mountingsurface (the abc surface) of the low profile PCI expansion board 61.

[0007] Also, the horizontal width of the PC card is regulated to be 54mm in the Physical Specification (P.31) for the PC Card Standard. Thus,it is difficult to develop a PC card slot mountable on the low profilePCI expansion board. Further, since a bracket position for the PCIexpansion card is also regulated, it is impossible to mount the PC cardslot in the ac direction in which the PC card is inserted or removed.Thus, it is difficult to use a PC card on an electronic apparatusemploying a low profile PCI.

[0008] It is a main object of the present invention to provide atechnology to allow an electronic apparatus employing a low profile PCIto mount a PC card thereon while using a conventional PC card slot.

[0009] An electronic apparatus of the present invention comprises: afirst board provided with an expansion connector for connecting with abus; a second PCI-compliant low profile board provided with a connectionterminal to be inserted into the expansion connector; an expansion unitprovided with a PC card slot for mounting a PC card thereon; and acabinet provided with a PC card insertion/removal opening, wherein theexpansion unit is placed in parallel to the second board, and the PCcard insertion/removal opening is placed in parallel to the PC cardslot.

[0010] The expansion unit of the electronic apparatus of the presentinvention may comprise a third board on which the PC card slot ismounted.

[0011] Further, the expansion unit of the electronic apparatus of thepresent invention may have the height, from the first board, lower thanthat of the second board.

[0012] Furthermore, the electronic apparatus of the present inventionmay have a space between the expansion unit and the connection terminalon the second board so that the second board can be inserted into theexpansion connector.

[0013] The other objects, features and advantages of the presentinvention will be apparent from the drawings and following explanations.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0014]FIG. 1 is an external view of a desktop type personal computer onwhich a PCI expansion adapter of the present invention is mounted;

[0015]FIG. 2 is a view of the PCI expansion adapter of the presentinvention when viewed from an expansion slot insertion/removal openingof an embodiment in which the PCI expansion adapter is mounted on thedesktop type personal computer;

[0016]FIG. 3 is a side view of an embodiment of the PCI expansionadapter of the present invention mounted on the desktop type personalcomputer with a cabinet cover removed;

[0017]FIG. 4 is a side view of an embodiment of the PCI expansionadapter of the present invention;

[0018]FIG. 5 is an embodiment of a low profile PCI expansion boardconstituting the PCI expansion adapter of the present invention;

[0019]FIG. 6 is an embodiment of the expansion unit constituting the PCIexpansion adapter of the present invention;

[0020]FIG. 7 is an embodiment of a PC card slot 33, which is anembodiment of the structure which dissipates the static electricity fromthe PCI expansion adapter;

[0021]FIG. 8 is a view from the direction parallel to a motherboard ofan embodiment where the PCI expansion adapter of the present inventionis inserted into the PCI expansion connector of the desktop typepersonal computer;

[0022]FIG. 9 is a sectional view of an embodiment where the PCIexpansion adapter of the present invention is inserted into the PCIexpansion connector of the desktop type personal computer;

[0023]FIG. 10 is a view of an embodiment where the PCI expansion adapterof the present invention is inserted into the PCI expansion connector ofthe desktop type personal computer viewed from right above themotherboard;

[0024]FIGS. 11A and 11B are side views of other embodiments of the PCIexpansion adapter of the present invention;

[0025]FIG. 12 is a side view of another embodiment of the PCI expansionadapter of the present invention;

[0026]FIG. 13 illustrates an embodiment where static electricity isremoved from the expansion unit;

[0027]FIG. 14 is an embodiment where the PC card slot is mounted on thelow profile PCI expansion board;

[0028]FIG. 15 illustrates an example of a PC card ejecting mechanism;

[0029]FIG. 16 illustrates an example of a PC card protection cover; and

[0030]FIG. 17 illustrates an example of mounting the PCI expansionadapter provided with the PC card slot onto the motherboard.

DETAILED DESCRIPTION OF THE INVENTION

[0031] With reference to the attached drawings, embodiments of thepresent invention will be explained in detail below. In the drawings, aninsertion/removal direction of the PC card with respect to the PCIexpansion adapter of the present invention corresponds to the abdirection, and an insertion/removal direction of the PCI expansionadapter with respect to the PCI expansion connector on the motherboardcorresponds to the ac direction.

[0032] First, the PCI expansion adapter of this embodiment will beexplained by using FIG. 1 to FIG. 10.

[0033]FIG. 1 is an external view of an information processing apparatusincorporating the PCI expansion adapter 1 of the present invention. Inthis embodiment, the information processing apparatus 50 is adisplay-integrated personal computer. The information processingapparatus 50 is provided with a display part 221, a main unit cabinet222 which includes a motherboard 51, and a protection cover 223.

[0034] Furthermore, a work plane is provided on the right side of theinformation processing apparatus in the main unit cabinet 222, whenviewed from the front (display), and the work plane is provided with aplurality of PC card insertion/removal openings 224 and variousconnectors 225. A PC card inserted from the PC card insertion/removalopening 224 is inserted into a PC card slot 33 of the PCI expansionadapter 1 so as to be electrically connected to the PCI expansionadapter 1.

[0035] The main unit cabinet 222 houses the motherboard 51 to which thePCI expansion adapter 1 is mounted. Here, the “motherboard” refers tothe board as a main part of the information processing apparatus, onwhich a CPU, a main memory, and various boards such as a daughter boardand an expansion board are mounted and mutually connected, and whichboard further includes various buses such as a local bus and a PCI buscontains for transmitting data signals.

[0036]FIG. 17 shows how the PCI expansion adapter 1 is mounted on themotherboard 51. The motherboard is provided with a PCI expansionconnector 52. As will be explained later, the PCI expansion adapterincludes a board 2 which can be inserted to and removed from the PCIexpansion connector 52, and an expansion unit 3 provided with a PC cardslot 33 which is the electrical connection means with a PC card, whichboards are mutually and electrically connected via stacking connectors22 and 32 provided on the respective boards.

[0037] As shown with a dotted line in FIG. 1, the motherboard 51 is seton the display side as the front of the cabinet interior and the PCIexpansion adapter 1 is mounted on the surface of the motherboard 51opposite to the surface facing the display.

[0038] Then, the structure for fixing the PCI expansion slot 1 to theinformation processing apparatus 50 will be explained by using FIG. 2and FIG. 3. FIG. 2 is an enlarged view of the expansion slot 55 on thework plane of the main unit cabinet 222 viewed from theinsertion/removal opening side. FIG. 3 shows the motherboard 51 with apart of the cabinet cover 56 of the desktop type personal computer 50removed, viewed from the back of the information processing apparatus50.

[0039] The PCI expansion adapter 1 is fastened to a bracket 25 via ascrew 29 and a washer 30. The bracket 25 is a structural material to fixthe PCI expansion adapter 1 to the main unit cabinet 222 and fixed tothe cabinet cover 56 via a screw 53. The PCI expansion adapter 1 isfixed to the cabinet via the bracket 25 and also inserted into the PCIexpansion connector 52 which is mounted on the motherboard 51.

[0040] The expansion slot 55 is formed on the main unit cabinet 222 forthe insertion of the PC card 54, and the PC card 54 is inserted from theexpansion slot 55 into the PC card slot 33 of the PCI expansion adapter1.

[0041] Then, the structure of the PCI expansion adapter 1 of the presentinvention will be explained using FIG. 4 to FIG. 7. The PCI expansionadapter 1 is constructed from the board 2 to be inserted into andremoved from the PCI expansion connector 52 on the motherboard of theinformation processing apparatus, and the expansion unit 3 provided withthe PC card slot 33 which is the means for electrical connection withthe PC card, while both boards are mutually and electrically connectedvia the stacking connectors 22 and 32 on the respective boards.

[0042] The board 2 is a PCI expansion card compliant with the lowprofile PCI standard and connected with the PCI bus on the motherboard,which board will be referred to as a “low profile PCI expansion board”.The expansion unit 3 includes the PC card slot 33 to install a PC cardthereto and is used to transmit and receive data signals between the PCcard and a CPU or the like. The board 2 and expansion unit 3 are alsofixed via supporting members such as a screw 35, which will be describedlater.

[0043] Furthermore, although this embodiment describes the case of theexpansion unit 3 mounting a PC card thereon, the expansion unit 3 maycarry an IC card reader/writer which writes and reads data to and froman IC card, for example, used for personal authentication, other thanthe PC card slot 33. Furthermore, anything other than the PC card slotor IC card reader/writer can also be mounted, if the configuration ofthe present invention is valid because it is not possible to mount thePC card on the existing low profile PCI board.

[0044] The low profile PCI expansion board 2 and expansion unit 3 arefixed using the bracket 25, screw 29 and washer 30 as shown in FIG. 2and FIG. 3. These are connected via the stacking connectors 22 and 32and are also mutually fixed via support members such as a spacer 26,screw 35, nut 27, washers 28 and 36.

[0045] The support structure of the low profile PCI expansion board 2and expansion unit 3 will be explained below. On the board 31, a drillhole 34 is provided directly beneath a board fixing screw hole 37 of thePC card slot. FIG. 6 shows a positional relationship between the boardfixing screw 37 and the drill hole 34. The spacer 26 is fixed to theboard 21 via the nut 27 and washer 28. When the stacking connectors 22and 32 are engaged, the spacer 26 contacts the board fixing screw hole37 of the PC card slot and maintains the distance between the lowprofile PCI expansion board 2 and expansion unit 3. Furthermore, thescrew 35 is passed through the washer 36, drill hole 34 and board fixingscrew hole 37, and screwed into the spacer 26, so that the board 31 andthe spacer 26 are fixed.

[0046] The above-described configuration allows the low profile PCIexpansion board 2 and expansion unit 3 to be mechanically fixed and canreduce the stress generated on the stacking connectors 22 and 32 whenthe PC card is inserted or removed. This method is also effective formechanically fixing the low profile PCI expansion board 2 and expansionunit 3 when using other connecting means such as a cable or flat cable,which has difficulty in supporting those, instead of the stackingconnectors 22 and 32.

[0047]FIG. 5 is a front view of the low profile PCI expansion board 2.There are two types of low profile PCI expansion board 2, namely for 5 Vand 3.3 V, which are different in position of the key slot 24 a of theconnection terminal 24. The positions of the key slot 24 a correspond tothe PCI expansion connectors 52 for 3.3 V and 5 V on the motherboardrespectively, and are intended to prevent wrong insertion into thedifferent type of PCI expansion connector. The example in FIG. 5 shownsa low profile PCI expansion board for 5 V, however the present inventionis applicable to any card as long as satisfying the low profile PCIexpansion board standard, and not limited to the 5 V card.

[0048] In the low profile PCI expansion board 2 in FIG. 5, the surfacewhere the key slot 24 a of the connection terminal for the 5 V PCIexpansion card is provided at the right end is called as “parts mountingsurface” (“primary side” or “component side B”), and the oppositesurface is called as “back surface” (“secondary side” or “component sideA”). In this embodiment, the parts mounting surface faces the expansionunit 3, and FIG. 5 shows the parts mounting surface.

[0049] The parts mounting surface of the low profile PCI expansion card2 is provided with a PC card control LSI 23 which controls theinput/output of data between the PCI bus and PC card. It is alsoprovided with the stacking connector 22 to transmit various signals withthe expansion unit 3. The stacking connector 22 may also be any otherelectrically connecting means such as a cable, electric wire or flexibleboard.

[0050] In this embodiment, the PC card control LSI 23 is mounted on thesame side of the board 21 as the side on which the stacking connector 22is installed, that is, the side facing the expansion unit 3. Not onlythe PC card control LSI 23 but also other mounting parts (not shown)other than the spacer 26, nut 27, washers 28 and 30, screw 29 aremounted on the side on which the stacking connector 22 of the board 21is installed. By such the one-side mounting, it becomes possible to makethe PCI expansion adapter thinner, and to reduce the number of man-hoursfor mounting parts.

[0051]FIG. 6 is a front view of the surface of the expansion unit 3facing the low profile PCI expansion board. The expansion unit 3 of thisembodiment is provided with the board 31, and the PC card slot 33explained below. Furthermore, the stacking connector 32 for transferringsignals to/from the low profile PCI expansion board 2 is also installedon the expansion unit 3. The stacking connector 32 is engaged with thestacking connector 22 installed on the low profile PCI expansion board 2to electrically connect the low profile PCI expansion board 2 andexpansion unit 3. The stacking connector 32 may also be any otherelectrically connecting means such as a cable, electric wire andflexible board, as same with the case of the stacking connector 22.

[0052]FIG. 7 illustrates an example of the PC card slot 33. The PC cardslot 33 in FIG. 7 is constructed from a board fixing screw hole 37, a PCcard guide 38, a connector 39 and a metal part 40. The PC card slot 33is not limited to a commercially available PC card slot, but may be anyproduct having electrically connecting means with a device having a PCIbus interface.

[0053] Returning to FIG. 6, the expansion unit 3 of this embodiment hasthe PC card slot 33 on the surface on which the stacking connector 32 ofthe board 31 is mounted. That is, the expansion unit 3 mounts the PCcard slot 33 on the surface facing the low profile PCI expansion board2. On the surface on which the stacking connector 32 of the board 31 ismounted, the PC card slot 33, and mounting parts other than the screw 35and washer 36 for supporting the expansion unit 3 are mounted. Thus, theone-side mounting is also applied to the expansion unit 3. Theabove-described configuration can make the PCI expansion adapterthinner, and also reduce the number of man-hours required for partsmounting.

[0054]FIG. 8 shows a front view of the PCI expansion adapter 1 mountedon the PCI expansion connector 52 on the motherboard 51 viewed from theunder side of the information processing apparatus in the directionparallel to the motherboard 51. The connection terminal 24 of the lowprofile PCI expansion board 2 is inserted in PCI expansion connector 52,and the PCI expansion adapter 1 is electrically connected to themotherboard 51.

[0055] Dotted lines show outlines of the parts seen through. The “c”direction in FIG. 8 indicates the display side of the informationprocessing apparatus, and the “a” direction indicates the back side ofthe information processing apparatus. The front side of FIG. 8 indicatesthe expansion unit 3, and the board behind the expansion unit 3 is thelow profile PCI expansion board 2.

[0056] Thus, this embodiment adopts a configuration with theinsertion/removal opening 224 of the PC card placed on the right sideviewed from the display, and therefore the parts mounting plane of thelow profile PCI expansion board 2 faces downward.

[0057] Furthermore, the PC card slot 33 may be placed on the expansionunit 3 at the left side in FIG. 8, that is, near the insertion/removalopening, or may also be placed at the right side in FIG. 8, that is,distant from the insertion/removal opening.

[0058] For the reasons relating to the sizes of the insertion/removalopening and the PC card, the PC card slot 33 is normally placed close tothe insertion/removal opening. This is associated with the constraintsof the standard of the PC Card Standard Physical Specification.

[0059] In the case that a wireless LAN card is used, for example, it maybe placed distant from the insertion/removal opening. The wireless LANcard requires an antenna section for wireless communications, and has ashape in which the outline of a normal PC card extends in thelongitudinal direction. Therefore, when the wireless LAN card isinserted in the PC card slot 33 placed near the insertion/removalopening, the antenna section bulges considerably from theinsertion/removal opening, which not only prevents the cover of thecabinet from closing, but also provides awful looking or collides withother objects to cause breakage, etc. In the case of placing it distantfrom the insertion/removal opening, it may be also possible to combineit with some ejecting mechanism so as to facilitate the ejection of thePC card of a normal size.

[0060]FIG. 15 shows an example of the ejecting mechanism. FIG. 15(a)shows a state of the ejecting mechanism before pushing an eject button,and FIG. 15(b) shows a state of the ejecting mechanism after pushing theeject button. Dotted lines in FIG. 15 show outlines of parts seenthrough. The structure is not limited to the one shown in FIG. 15 andcan be any structure as far as it allows the PC card to be ejectedeasily.

[0061] The ejecting mechanism in FIG. 15(a) is constructed from the PCcard slot 33, an eject button 200 and metal parts 201 to 203. As shownin FIG. 15(b), the connector section 39 of the PC card slot 33 isprovided with a protrusion 204, which serves as the fulcrum when themetal part 202 rotates. Furthermore, a depression is provided in thepart which contacts the protrusion 204 of the metal part 202 so that themetal part 202 rotates smoothly.

[0062] Then, the PC card ejection operation will be explained. First, asshown in FIG. 15(a), the eject button 200 is pushed in the directionindicated by the arrow. The metal part 201 fixed to the eject button 200is slid along the PC card slot 33 in the ab direction. Furthermore, themetal part 202 fixed to the metal part 201 at one end in such a way thatit operates slowly is rotated around the protrusion 204 in the directionindicated by the arrow. The metal part 203 fixed to the other endopposite to the end of the metal part 202 connected to the metal part201 in such a way that it operates slowly is pushed in the directionindicated by the arrow and physically pushes the PC card.

[0063] Furthermore, in the case that the PC card slot 33 is placeddistant from the insertion/removal opening and a PC card of a normalsize is used, by providing a mechanism which protects theinsertion/removal opening, it is possible to prevent the board frombeing damaged due to dust from the outside.

[0064]FIG. 16 shows an example of a mechanism of protecting theinsertion/removal opening. This mechanism is not limited to that in FIG.16, while any mechanism can be used, as far as it can protect theinsertion/removal opening.

[0065]FIG. 16 is constructed from a rotation axis 205, fixing devices206 and 207, and a protection door 208. FIG. 16(a) shows a state of themechanism before the door 208 is closed, and FIG. 16(b) shows a state ofthe insertion/removal opening protected by closing the protection door208.

[0066] As shown FIG. 16(a), the protection door 208 is rotated aroundthe rotation axis 205, whereby the fixing devices 206 and 207 areengaged with each other to fix the protection door 208.

[0067] In the case of the configuration in which the insertion/removalopening is provided on the left side viewed from the front of theinformation processing apparatus, the parts mounting surface of the lowprofile PCI expansion board faces upward, contrary to the configurationof this embodiment.

[0068] The low profile PCI expansion board 2 has external dimensionscompliant with the low profile PCI standard. Further, the height of theexpansion unit 3 from the motherboard 51 is equal to that of the lowprofile PCI expansion board 2. However, the height of the expansion unit3 when connected with the low profile PCI expansion board 2 via thestacking connectors 22 and 32 is not necessarily equal to that of thelow profile PCI expansion board 2 but can be lower than that of the lowprofile PCI expansion board 2.

[0069] Thus, there is provided a space between the low profile PCIexpansion board 2 and the expansion unit for insertion into the PCIexpansion connector 52 on the motherboard 51 so that the PC card slot 33is placed in this space. Therefore, when the PCI expansion adapter 1 ismounted on the motherboard 51, the PC card slot 33 is placed between thePCI expansion connector 52 and the expansion unit 3 as shown by dottedlines.

[0070] Then, the constraints with respect to the width of the PCIexpansion adapter 1 of this embodiment and the distance between the lowprofile PCI expansion board 2 and expansion unit will be explained. Thewidth of the PCI expansion adapter 1 refers to the width H1, forexample, in FIG. 4 from the nut 27 of the low profile PCI expansionboard 2 to the head of the screw 35 on the expansion unit 3. On theother hand, the distance between the low profile PCI expansion board 2and expansion unit refers to the distance H2 between the connectionterminal 24 on the low profile PCI expansion board 2 and the facingsurface of the expansion unit.

[0071] The PCI Local Bus Specification Version 2.2 (P.146) defines thewidth of the PCI expansion connector 52 to be 8.89 mm. Furthermore, whena plurality of PCI expansion connectors 52 are placed in parallel on themotherboard 51, the PCI Local Bus Specification Version 2.2 defines thedistance between the neighboring PCI expansion connectors 52 to be 20.32mm. According to this specification, if the width of the PCI expansionadapter 1 is 20.32−8.89/2=15.875 mm or less, it is possible to mount aplurality of PCI expansion adapters 1 on the connectors installed on themotherboard 51 at intervals of 23.32 mm.

[0072] However, according to the PCI Local Bus Specification Version 2.2and the ECN concerning and low profile PCI card, there are providedconstraints of the mounting of parts, and thus, the width of the PCIexpansion adapter 1 is actually 14.48 mm or less. That is, the heightfrom the parts mounting surface of the PCI expansion board 2 to theexpansion unit 3 cannot exceed 14.48 mm, due to the constraintsaccording to the standard, as follows.

[0073] (1) The height of the rear of the low profile PCI expansion board2 is 2.67 mm or less.

[0074] (2) The height of the parts mounting surface of the low profilePCI expansion board 2 is 14.48 mm or less,

[0075] The foregoing explanation describes the maximum value of thewidth of the PCI expansion adapter 1, while the minimum value will beexplained below. The distance between the mutually facing surfaces ofthe low profile PCI expansion board 2 and the expansion unit 3 is halfthe width of the PCI expansion connector 52, that is, 4.445 mm plus theheight of the PC card slot. Since the height of the existing PC cardslot used in this embodiment is 7.65 mm, the distance is required to beat least 12.095 (=7.65+4.445) mm. Therefore, the width of the PCIexpansion adapter 1 of this embodiment is not less than 12.095 and notmore than 14.48 mm. Furthermore, the distance between the low profilePCI expansion board 2 and expansion unit is obtained by subtracting thethickness of the board 21 of the low profile PCI expansion board 2 andthe thickness of the board 31 of the expansion unit 3 from the width ofthis PCI expansion adapter 1. Under these constraints, by reducing thewidth of the PCI expansion adapter 1, it is possible to reduce the sizeof the information processing apparatus 51.

[0076] Furthermore, in this embodiment, the position of the PC card slot33 is shifted so that it does not physically interfere with other partssuch as the PC card control LSI 23. That is, by mounting a part such asthe PC card control LSI whose height is lower than the PC card slot 33whose height is 7.65 mm while shifting from the PC card slot 33, it ispossible to suppress the required distance between the low profile PCIexpansion board 2 and the expansion unit 3 to the minimum width of thePCI expansion adapter 1. Furthermore, even when a part higher than thePC card slot 33 is mounted, by shifting its position so that it does notinterfere with the PC card slot 33, it is possible to make the distancebetween the low profile PCI expansion board 2 and the expansion unit 3within the above-described range.

[0077]FIG. 10 is a top view of the configuration in which two PC cardslots are placed in parallel viewed from right above the motherboard 51.The thickness of the board 21 of the low profile PCI expansion board 2and the thickness of the board 31 of the expansion unit are both 1.6 mm,and the distance between the low profile PCI expansion board 2 and theexpansion unit 3 when connected via the stacking connectors 22 and 32 is8 mm. The overall width of the PCI expansion adapter 1 in considerationof screws, etc. is 11.2 mm.

[0078] Since the overall width of the PCI expansion adapter 1 is 11.2mm, even when two or more PCI expansion adapters 1 are connected, theneighboring PCI expansion adapters 1 do not physically interfere witheach other, that is, can be mounted in parallel without contacting witheach other. Furthermore, in one PCI expansion adapter 1, a part mountedon the low profile PCI expansion board 2 and the expansion unit 3 isplaced in such a way that they will not physically interfere with a partmounted on the other board as a connecting object.

[0079] However, not only the parts in the configuration adopted in thisembodiment, but also any other parts including the PC card control LSI23 can be mounted arbitrarily, as far as the constraints of theabove-described “PCI Local Bus Specification Ver. 2.0” are satisfied.Due to the constraint of the height of the rear of the low profile PCIexpansion board 2, the expansion unit 3 must be connected in the currentdirection, but both the low profile PCI expansion board 2 and expansionunit 3 can mount a part on both surfaces thereof. Furthermore, the PCIexpansion adapter 1 can also mount a part such as a PC card slot in theways shown in FIGS. 11A, 11B and 12.

[0080] In FIG. 11A, the PC card slot 33 is mounted on the surfaceopposite to the surface on which the stacking connector 32 of the board21 is mounted. On the other hand, FIG. 11B shows an example where the PCcard slot 33 is placed near the insertion/removal opening to facilitatethe removal of the PC card from the cabinet. This is the example suitedto a case where the PC card does not have a protrusion such as anantenna section of a wireless LAN card.

[0081] Furthermore, it is also possible to extend the side in the abdirection of the board 31 of the expansion unit 3 and mount the PC cardcontrol LSI 23 on that area of the board 31. This embodiment iseffective when there are no structural constraints of the electronicapparatus regarding the length in the ab direction, and further, makesit possible to narrow the width of the PCI expansion adapter 1.

[0082] As shown above, a space allowing insertion into the PCI expansionconnector is provided between the connection terminal 24 of the lowprofile PCI expansion board 2 and the expansion unit provided with thePC card slot. By adopting such a configuration that prevents theexpansion board from physically interfering with the PCI expansionconnector, it is possible to satisfy the low profile PCI expansion boardstandard and connect a low profile expansion PCI card and the existingPCI expansion slot as well.

[0083] Furthermore, the PC card control LSI 23 of the low profileexpansion PCI card is placed as close as possible to the connectionterminal 24 and stacking connector 22. Such a layout shortens the wiringlength between the PC card control LSI 23 and connection terminal 24 andits distance to the stacking connector 22, thus suppressing generationof noise.

[0084] As described above, in addition to the low profile PCI expansionboard 2, the expansion unit 3 on which a PC card is mounted is providedand a space for insertion into the PCI expansion connector 52 on themotherboard 51 is formed between the low profile PCI expansion board 2and the expansion unit 3. Thus, the PC card slot 33 is placed betweenthe low profile PCI expansion board 2 and the expansion unit. Theabove-described configuration satisfies the low profile PCI standard andat the same time allows an existing PC card slot to be mounted on thelow profile PCI card of external dimensions compliant with the lowprofile PCI standard.

[0085] Furthermore, by keeping the size of the PCI expansion adapterwithin the dimensional specification of the low profile PCI expansionboard, it is possible to reduce the size of the desktop type personalcomputer.

[0086] Furthermore, by optimizing the layout of parts such as the PCcard slot, it is possible to make the PCI expansion adapter smaller andthinner.

[0087] Furthermore, by mechanically fixing the low profile PCI expansionboard and the expansion unit which constitute the PCI expansion adapterby using the board fixing structure of the PC card slot, the structurecan be strengthened.

[0088] Furthermore, by placing the PC card control LSI near the meansfor electrical connection with the PCI bus and shortening the wiringlength between the PCI bus and PC card control LSI, the generation ofnoise can be suppressed.

[0089] Then, the mechanism of dissipating static electricity from thePCI expansion adapter 1 of the above-described embodiment will beexplained using FIG. 13 and FIG. 7. The bracket 25, the spacer 26, thescrew 35, the screw 29, the washer 30 and the metal part 40 areelectrically conductive parts. The metal part 40 on the PC card slot 33shown in FIG. 7 has a structure whereby the metal part 40 physicallycontacts the PC card and also electrically connects with the screw 35through the board fixing screw hole 37. Furthermore, the screw 35 andspacer 26 are electrically connected with a pad with a solid pattern onthe board 21. Furthermore, the bracket 25 is electrically connected withthe solid pattern on the board 21 through another pad via the screw 29and the washer 30.

[0090] Therefore, as shown by the arrow in FIG. 13, the staticelectricity charged on the PC card flows into the cabinet ground throughthe path formed by the metal part 40, screw 35, spacer 26, solid patternon the board 21 and bracket 25. The above-described configuration canprovide an anti-static-noise measure for a PC card on the expansionunit, which has no direct contact with the cabinet.

[0091] As explained above, the present invention allows an existing PCcard slot to be used to expand a PC card on an electronic apparatususing a PCI expansion adapter of external dimensions compliant with thelow profile PCI standard.

What is claimed is:
 1. A PCI expansion adapter for a PC card,comprising: a first PCI-compliant low profile board provided with aconnection terminal for connecting with a bus provided on a main boardof an electronic apparatus; an expansion unit provided with a PC cardslot for accepting the PC card, which is placed in parallel to the firstboard; and an expansion unit connection mechanism for connecting thefirst board and the expansion unit.
 2. A PCI expansion adapter for a PCcard according to claim 1, wherein said expansion unit connectionmechanism comprises a first stacking connector mounted on said firstboard and a second stacking connector mounted on said expansion unit. 3.A PCI expansion adapter for a PC card according to claim 2, wherein theheight of said first and second stacking connectors engaged with eachother is 4.45 mm or more.
 4. A PCI expansion adapter for a PC cardaccording to claim 1, wherein said first board has a first surfacefacing said expansion unit, and said expansion unit has a second surfacefacing the first board, and wherein the distance between said firstsurface and said second surface is 4.45 mm.
 5. A PCI expansion adapterfor a PC card according to claim 4, wherein said expansion unit has athird surface opposite to the second surface, and wherein the heightfrom said first surface to the highest projection end on the thirdsurface is 14.48 mm or less.
 6. A PCI expansion adapter for a PC cardaccording to claim 4, wherein said expansion unit is provided with saidPC card slot on said second surface.
 7. A PC card expansion adapter fora PC card, comprising: a first PCI-compliant low profile board provided,at one edge thereof, with a connection terminal to be inserted into aPCI expansion connector mounted on a main board of an electronicapparatus; an expansion unit provided with a PC card slot; and aconnection member for transmitting a signals between said PCI-compliantlow profile board and said expansion unit, wherein the inserting andremoving direction of a PC card with respect to said PC card slot is thesame as that of said edge provided with said connection terminal of saidfirst board.
 8. A PCI expansion adapter for a PC card according to claim7, wherein said connection member comprises a first stacking connectormounted on said first board and a second stacking connector mounted onsaid expansion unit.
 9. A PCI expansion adapter for a PC card accordingto claim 8, wherein the height of said first and second stackingconnectors engaged with each other is 4.45 mm or more.
 10. A PCIexpansion adapter for a PC card according to claim 7, wherein said firstboard has a first surface facing said expansion unit, and said expansionunit has a second surface facing the first board, and wherein thedistance between said first surface and said second surface is 4.45 mm.11. A PCI expansion adapter for a PC card according to claim 10, whereinsaid expansion unit has a third surface opposite to the second surface,and wherein the height from said first surface to the highest projectionend on the third surface is 14.48 mm or less.
 12. A PCI expansionadapter for a PC card according to claim 10, wherein said expansion unitis provided with said PC card slot on said second surface.
 13. A PCIexpansion adapter comprising: an expansion board provided with aconnection terminal to be connected with a PCI expansion connectormounted on a motherboard provided with a bus for transmitting data; anexpansion unit provided with a PC card slot for accepting said PC card;and a connector for connecting the expansion board and the expansionunit with each other, wherein the distance between said connectionterminal of said expansion board and said expansion unit is 4.45 mm ormore.
 14. A PCI expansion adapter according to claim 13, wherein saidconnector comprises a first stacking connector mounted on said expansionboard and a second stacking connector mounted on said expansion unit.15. A PCI expansion adapter according to claim 14, wherein the height ofsaid first and second stacking connectors when engaged with each otheris 4.45 mm or more.
 16. A PCI expansion adapter according to claim 13,wherein said expansion board has a first surface facing said expansionunit, and said expansion unit has a second surface facing the expansionboard, and wherein the distance between said first surface and saidsecond surface is 4.45 mm.
 17. A PCI expansion adapter according toclaim 16, wherein said expansion unit has a third surface opposite tothe second surface, and wherein the height from said first surface tothe highest projection end on said third surface 14.48 mm or less.
 18. APCI expansion adapter according to claim 16, wherein said expansion unitis provided with said PC slot on said second surface.